/*
     * Listing 3:
     * Handling short writes
     * Ivan Griffin (ivan.griffin@ul.ie)
     */
    int bytesToSend = 0,
        bytesWritten = 0,
        num = 0;

    /*
     * somewhere here bytesToSend, buffer, and fileDesc must be
     * set up.
     */

    for (bytesWritten = 0; bytesWritten < bytesToSend;
         bytesWritten += num)
    {
        num = write(fileDesc,
            (void *)( (char *)buffer + (char *)bytesWritten ),
            bytesToSend - bytesWritten);

        if (num < 0)
        {
            perror("write()");

            if (errno != EINTR)
            {
                exit(1);
            }
        }
    }

Listing 3. Handling short writes.